Study on ammonia nitrogen and phosphorus removal using sequencing batch reactor

Abstract

Study on ammonia nitrogen and phosphorus removal using sequencing batch reactor Samaneh Alijantabar Aghouzi * Department of Chemical and Environmental Engineering, Faculty of Engineering Universiti Putra Malaysia, Serdang Malaysia   Thomas S. Y. Choong Sustainable Process Engineering Research Center (SPERC) Universiti Putra Malaysia, Serdang Malaysia   Aida Isma M. I. Centre for Water Research, Faculty of Engineering and the Built Environment SEGi University, Kota Damansara Malaysia   *Corrosponding author’s Email: sam.alijani@gmail.com                   Peer-review under responsibility of 3rd Asia International Multidisciplanry Conference 2019 editorial board (http://www.utm.my/asia/our-team/) © 2019 Published by Readers Insight Publisher, lat 306 Savoy Residencia, Block 3 F11/1,44000 Islamabad. Pakistan, info@readersinsight.net This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).     _________________________________________________________   Research Highlights   The highest phosphorus and ammonia nitrogen removal efficiencies were 99.5% and 51%, respectively, in 6 hours. Particle size of sludge reduced from 26 μm to 39.81 μm in 60 days. Fourier transform infrared spectroscopy (FTIR) showed that N-O, N–H, S=O and C=N compunds detected. ___________________________________________________________________________   Research Objectives   Ammonia nitrogen and phosphorus removal have becoming more rigorous in permits making it one of the most important and most difficult processes to maintain in wastewater treatment plants. Sequencing batch reactor is a controlled activated sludge process that is able to tackle ammonia nitrogen and phosphorus issues and has some benefits such as having a small-scale system and low construction cost (1). The main goal of this research is to investigate the ability of SBR in treating sewage containing phosphorus and ammonia nitrogen in 6 hours to achieve the allowable effluent discharge standard set by the Department of Environment Malaysia.     Materials and Methods   In this experiment, a sequencing batch reactor with a total volume of 7 L. The mechanical stirrer was used to avoid sludge settling with a speed of 100 rpm. A fine bubble diffuser was used to supply air. The operation time was controlled based on 1 h and 30 mins anaerobic, 2 h and 10 mins anoxic, 1 h and 50 mins aerobic, making the hydraulic retention time (HRT) of 6 hours. 10 L seed sludge and 30 L raw sewage samples were collected weekly from the sewage treatment plant that was located in Selangor and were kept under 4oC in cold room in order to obtain fresh samples. The sludge volume was 30% of raw sewage volume in the reactor and the reactor refilled with 3.5 liters of raw sewage at the start point of the experiment. The experiment was carried out in room temperature of  27±3 oC with the pH value ranging from 6 to 8 and dissolve oxygen value ranging from 0 to 6 mg/L. Phosphorus and ammonia nitrogen were measured according to the APHA method (2). DO and PH were measured by using DO meter (JPB-70A) and PH meter (CT-6821, Shenzhen Kedida Electronic CO).     Results   The highest ammonia nitrogen removal efficiencies observed to be 31.9 %, 10.3 % and 38.8 % at the respective phases of anaerobic, anoxic and aerobic, respectively. Results showed that the phosphorus removal efficiencies for anaerobic, anoxic and aerobic phases were 70.43 %, 19.16%, and 98.58%, respectively in 6 hours. The highest phosphorus removal efficiency recorded was 98.58% that took place in the aerobic phase because of the absence of sufficient nitrate which can inhibit phosphorus uptake during the aerobic phase. The most sensitive process is nitrification that helps to biological oxidation of ammonia to nitrate, which is performed by two types of microorganisms, i.e. ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) (3). Karl et al. claimed that toxic substances inhibit the metabolism of bacteria (4). Mino et al. (5) also stated that nitrification process will not be accomplished in anaerobic phase without the presence of nitrate. This will affect the phosphorus uptake in the aeration phase.   Findings   FTIR spectrum shows that N-O, N–H, S=O and C=N compounds were identified in the sludge. The presence of these compounds might affect the nitrification and denitrification processes and indirectly affecting the degradation the ammonia nitrogen and phosphorus. Sewage sample might also contain heavy metals as the sewage treatment plant was located in the industrial area.     Acknowledgment   The authors gratefully thank the financial and research support of Universiti Putra Malaysia.   References Sathian, S, M Rajasimman, C S Rathnasabapathy, and C Karthikeyan. 2014. “Journal of Water Process Engineering Performance Evaluation of SBR for the Treatment of Dyeing Wastewater by Simultaneous Biological and Adsorption Processes.” Journal of Water Process Engineering 4: 82–90. APHA. Standard Methods For the examination of water and Wastewater 23rd ed. ed. Washington, D.C.2017. Chang HN, Moon RK, Park BG, Lim S, Choi DW. Simulation of sequential batch reactor ( SBR ) operation for simultaneous removal of nitrogen and phosphorus. 2000;23. Karl DM, States U. Nitrogen Cycle ☆. 3rd ed. Encyclopedia of Ocean Sciences, 3rd Edition. Elsevier Inc.; 2018. 1-10 p. Mino T, Loosdrecht MCM van, Heijnen JJ. Microbiology and biochemistry of the EBPR process. Water Res. 1998;32(11):3193–207.